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Development of Electrochemical Thin-layer Degradation Cell for Oxidation Stress Testing of Active Pharmaceutical Ingredients
Šefčík, Martin ; Kubíčková, Anna (advisor) ; Coufal, Pavel (referee)
In this thesis, the oxidation conditions in a new electrochemical "thin-layer" flow-through cell for the study of the oxidative degradation of active pharmaceutical ingredients were optimized. In this field, it is an innovative approach to studying the oxidation properties of substances. The cell was manufactured using 3D printing technology. Oxidation was carried out in a two-electrode arrangement with a working boron-doped diamond electrode (BDDE) and an auxiliary stainless steel electrode. Optimization of conditions was performed using salicylic acid as a model active pharmaceutical ingredient. The electrochemical approach was used to degrade this active pharmaceutical ingredient by the required approximately 20% of the original amount in only 2.3 min. Thus, the degradation time was significantly reduced compared to the oxidative stability stress tests of active pharmaceutical ingredients commonly used today. Two major degradation products were observed, namely gentisic acid and 2,3-dihydroxybenzoic acid. The degradation products obtained by electrochemical oxidation and chemical oxidation using hydrogen peroxide are identical.
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Macrocyclic ligands for selective complexation of large cations
Šefčík, Martin ; Kotek, Jan (advisor) ; Vojtíšek, Pavel (referee)
4 Abstract Nowadays, macrocyclic complexes of actinides receive an increasing attention for their potential applications in radiotherapy. It requires significant demands on their thermodynamic and kinetic stability which are particularly influenced by an appropriate choice of a ligand. This Thesis focuses on a synthesis and characterization of two ligands that are potentially applicable for complexation of lanthanum as a model of radioactive actinium. Both ligands are based on a fifteen-membered cycle containing pyridine group, 15-pyN3O2. The first ligand, H4L1, contains two phosphonate pendant arms. The second ligand, H2L2, contains two phosphinate pendant arms. Both compounds were prepared and characterized. Keywords Macrocyclic ligands, large cations, phosphonic acids, phosphinic acids, dissociation constants
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